Ultra high frequency switch



Aug. 26, 1947. o. E. DOW

ULTRA HIGH FREQUENCY S'ITCH Original Filed June 10, 1942 OrrdZeEfi o w A r70 .QNE v Patented Aug. 26, 1947 2,426,186 ULTRA men FREQUENCY swrrcn OrvilleE. Dow, Port Jeflerson, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Original application June 10, 1942, Serial No. 446,457. Divided and this application June 23, 1943, Serial No. 491,893

' 7 Claims.

1, My present invention relates to ultra high frequency switches. One general object of my invention is to provide improved methods and means for controlling the flow of ultra high frequency waves.

certain systems utilizing ultra high frequency waves it becomes necessary to turn on an ultra short wave generator and subsequently turn it On as, for example, in a duplex or half duplex system where the transmitter is turned off during the receiving period. In such cases, if controlof the waves is accomplished by switching on and on operating voltages applied to the electron discharge device generator, large frequency drifts of the carrier occur when the translations generated prior to the time the transmitter is returned to the air after an interval of inactivity. This change in frequency becomes exceedingly large and objectionable when operating at frequencies above 500 megacycles and the condition is aggravated at frequencies above.

1000 megacycles.

This application is a divisional application of my copending application Serial No. 446,457, filed June 10, 1942, which contains claims directed to ultra high frequency circuits, whereas in this application claims are directed to a high fre- 1 quency switch for concentric transmission lines.

An object of this invention is to provide a new and useful ultra high frequency switch.

A feature of this invention is the novel arrangement of a rotary element of a high frequency switch wherein the continuity and electrical characteristics of a concentric line are main,- tained uniform throughout.

I have found that the above mentioned frequency shift or drift is due in large measure to the change in heating of the low frequency determining circuits employed in the generator as it is turned on and off. This change in frequency, therefore, could be substantially reduced by building low or zero temperature coillcient frequency determining circuits, but in most instances the cost of such circuits is not justified.

In accordance with my present invention, this difliculty is circumvented by utilizing the usual low loss resonator or tank circuit for frequency control and maintaining the power dissipated therein substantially constant in both the on" and o conditions of the oscillation generator. In this way, the temperature of the frequency controlling element is maintained substantially constant and, accordingly, the frequency of oscillations generated after a, period of inactivity is substantially the same as the frequency of oscilmitter was turned off.

ing the tank circuit. For this purpose I make use of a section oftransmission line for loading and unloading the tank circuit, as will be explained more fully hereinafter, whereby the tank circuit mayeasily be returned to its original frequency setting. a

It will be noted that the detuning control described herein is especially useful for frequencies above- 1000 megacycles where the oscillator efficiency is generally low. Hence, in these cases thepercentincrease in power dissipated in the oscillator when changed from the oscillating to the non-oscillatingcondition willbe small.

Further, I have found that when the oscillator. is turned on? by detuning in accordance with what has been said above, the power dissipated in the tank or frequency controlling circuit may not -be the same as the power dissipated in the circuit under oscillating conditions. Accordingly, my invention further contemplates the simultaneous detuning of the low loss tank circuit together with a change in voltage away from the optimum applied to certain electrodes of the generator. In this way, adjustments maybe made so that the frequency of operation is maintained substantially constant despite on and off switching of the system. Further objects, features, ad vantages and other factors to be considered in connection 'with my present invention will be given with the aid of the accompanying drawings, which, however, are not to be construed as limiting the principles of my present invention and wherein:

Fig. 1 is a cross-sectional view of the high frequency switch of this invention, and Fig. 2 is a bottom view of Fig. 1.

Referring now in detail to Figs. 1 and 2 of the drawing, care has been taken to keep the coupling low between coaxial fittings 3|, 32 and 33. 3| may be the coaxial cable or line section "I to the ultra high frequency transmitter, 32 goes to the receiver and 34 is the connection to the antenna, The fitting 33 is a spare. This switch was constructed for operation at about 3000 me. The insulators 54 are in pairs spaced one-quarter wave length apart and secured in place by set screws 58. The rotor plug or piston 35 may be rotated by means of handle 36 within cylinder 31. A cover 38 is secured to the cylinder 31 by means of a plurality of screws 38A. The spring washer 39 insures good contact of the ends of 3 rotor 85 with the bottom of cylinder 31, and its cover plate 38. The rotor 35 is-split in two parts on line 15A, the two parts being loosely secured together by means of a single screw 3513 to keep them in line when rotated by handle 36. The outer conductors of fittings-3|, 32, 83 and 34 are soldered intocylinder 31. The ends of the outer conductors are threaded at 51 with a %-24 thread. The inner conductors of II, 32 and 33 are heldrigidly in place by theirinsulators and have spring chucks or jacks 55 located at their outer ends to receive a single #18 gauge wire and have slots at their inner ends to receive the blade 56 at the end oi the inner conductor of 34. The inner conductor of 34 is held by insulators Ill, 42 rigidly withinthe elbow passage supported within said rotor.

4. An ultra high frequency switch comprising a metallic housin having a cylindrical aperture therein, a cylindrical rotor formed in two por-.

tions, each portion of said cylindrical rotor ar-: ranged with'means to rotate them together with-! in said cylindrical aperture in said metallic housing, a'plurality of transmission line conductors 'each having inner and outer conductors concen- H drilled in rotor 35. Hence, when 35 is rotated the inner conductor of 34 rotates and engages in turn the slots locatedat the end of the "inner conductors or 3|, 3 2 and 33. There is a bearing or rotating contact between the'lack end of 'the inner conductor of 34 and the inner conductor (not shown) of the cable or transmission line connected to 34. About the circumference of 35 is a central groove 48 the width of which is equal to or slightly less than the diameter of the inner conductors of Ii, 32 and 33. The sides of thi groove because of action of spring 39 and split'portion "A, the rotor plug will make good contact with and ground the inner conductors of the two coaxial lines not connected to the antenna conductor 34.

What I claim is 1. A high frequency switch comprising a cylindrical metallic casing, P ir of concentric transmission lines each having an inner conductor and an outer conductor supported by the side walls of said casing, the inner conductors of said transmission lines protruding into said casing, another concentric transmission line afllxed to the base of said casing, ametallic plugrotatable within said casing, said plug having insulating means for carrying the inner conductor of the concentric line aflixed to the base of said casing, and means for rotating said plug so that the inner conductor coming through the base may be selectively connected .to any one of the internal conductorscf the transmission lines connected to the side walls of said cylindrical casing, said plug being so arranged as to short-circuit the inner transmission line conductor which is not connected to the inner conductor coming through the base.

2. An ultra high frequency switch comprising a metallic housing having a cylindrical aperture therein, a cylindrical rotor arranged .to rotate within said cylindrical aperture, a plurality of transmission line conductors each having inner and outer conductors concentrically arranged and radially extending outward from said cylindrical aperture in said housing, a conducto insulatingly supported within said cylindrical r0- tor, and means to rotate said cylindrical rotor to connect one of the inner conductors of said transmission line conductors with the conductor which is insulatingly supported within said rotor.

3. An ultra high'frequency switch comprising a metallic housing having a cylindrical aperture therein, a cylindrical rotor arranged to rotate within said cylindrical aperture, a plurality of transmission line conductors each having inner andouter conductors concentrically arranged and radially extending outward from said cylindrical aperture in said housing, a conductor insulatingly supported within an elbow shaped aptricallyarranged and radially extending outward fromsaid cylindrical aperture in said housing, -a conductor insulatingly supported within said cylindrical rotor, and means to rotate with cylindrical rotor to connect one of th inner conductors of said transmission line conductors with the conductor which is insulatingly supported within said rotor.

6. An ultrahigh frequency switch comprising a metallic housing having a cylindrical aperture therein, a cover for closingsaid cylindrical aperture in said housing, a cylindrical rotor arranged to 'rotate' within said cylindrical aperture in said metallic housing, a plurality of transmission line conductor fittings each having inner and outer conductors concentrically arranged to give the same electrical characteristics as the conductors of the ultra high frequency circuits to be switched, a conductor insulatingly supported Within an aperture in said cylindrical rotor which has the same electrical characteristics as the conductors of the ultra high frequency circuit to be switched and means passing through said cover to rotate said cylindrical rotor to connect one of said transmission lines with the conductor which is insulatingly supported within said rotor.

6. A high frequency switch comprising a metallic housing into which a plurality of concentric transmission line conductor fittings are terminated, a metallic rotor element located within said metallic housing, conducting means insulatingly located within said rotor for .connecting .into .circuit the inner conductor 01' one ofsaid fittings of the concentric transmission lines and for simultaneously short circuiting the inner conductor of at least another transmission line.

7.- A high frequency switch comprising a metallic housing, a metallic rotor located within said metallic housing, said metallic rotor having an elbow passage located therein, a conductor passing through said elbow passage and insulatingly supported from said metallic rotor, a plurality of metallic fittings of transmission lines terminated and supported by said housing, said metallic rotor being so arranged with respect to the transmission lines that said conductor is con- 'nected to an inner conductor of one of the transmission lines while'said metallic rotor short'circults all 01' the remaining inner conductors of the transmission lines.

ORVILLE E. DOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,037,492 Kettering Sept. 3, 1912 393,756 Griscom Dec, 4, 1888 2,344,780 Kram Mar. 21, 1944 2,360,219 Goddard Oct. 10, 1944 

